Monolithic Power Systems Inc. MPQ2178GQHE-18-AEC1-P

Overview

MPQ2178GQHE-18-AEC1-P from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous step-down DC/DC converter delivering 2A continuous output at fixed 1.8V from 2.5V–6V input. It integrates 70mΩ P-channel and 40mΩ N-channel MOSFETs, employs constant-on-time (COT) control with VIN feed-forward, and features power good (PG), external soft-start, output discharge, and over-voltage protection - deployed in automotive clusters and telematics power rails.

For engineers reviewing the MPQ2178GQHE-18-AEC1-P datasheet, MPQ2178GQHE-18-AEC1-P pinout, MPQ2178GQHE-18-AEC1-P application, or MPQ2178GQHE-18-AEC1-P equivalent, key selection criteria include its 2.4MHz switching frequency for compact filtering, ±0.036V output regulation accuracy at 1.8V, -40°C to +150°C junction temperature operation, wettable flank QFN-8 package, and integrated FCCM mode for stable light-load efficiency.

Technical Context

The MPQ2178GQHE-18-AEC1-P implements a constant-on-time (COT) control architecture with VIN feed-forward to maintain stable 2.4MHz switching across input and load variations, eliminating loop compensation components. Its internal high-side P-channel and low-side N-channel MOSFETs enable 100% duty cycle operation for ultra-low dropout performance.

Fault management includes cycle-by-cycle current limiting (3.5A peak, 2A valley), thermal shutdown at 170°C with 20°C hysteresis, short-circuit protection with hiccup mode, and output over-voltage protection triggered at 115% of VREF (1.035V). The PG pin provides open-drain status with 90% rising / 85% falling thresholds relative to internal 0.6V reference.

Key Specifications

Pinout & Package

MPQ2178GQHE-18-AEC1-P is housed in a wettable flank QFN-8 package (1.5mm × 2mm, 0.5mm pitch), optimized for automated optical inspection (AOI) and solder joint reliability in automotive assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with MPQ2171GQ-AEC1-P, the MPQ2178GQHE-18-AEC1-P adds PG, soft-start, and 2A capability essential for complex SoCs; versus TPS6286418RTER, it delivers certified Grade 1 operation for under-hood and cluster deployment where thermal robustness is non-negotiable.

Availability

MPQ2178GQHE-18-AEC1-P is available at Aetrix Electronics and suitable for automotive clusters, ADAS camera modules, telematics units, and keyless entry systems requiring stable component supply with full AEC-Q100 traceability and long-term lifecycle support.

Supply support for MPQ2178GQHE-18-AEC1-P includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs for automotive, industrial, and consumer markets, with design centers in the US, China, and Taiwan.

The MPQ2178 belongs to MPS's automotive-qualified DC/DC converter product line, engineered specifically for demanding automotive subsystems requiring AEC-Q100 compliance, functional safety readiness, and high-density power conversion in harsh environments.

FAQ

What is the maximum allowable input voltage for MPQ2178GQHE-18-AEC1-P?

The absolute maximum input voltage is +6.5V for steady-state operation, with a brief 10ns pulse rating up to +7.5V. The recommended operating range remains 2.5V to 6V per datasheet specifications. Exceeding 6.5V risks permanent damage to the internal high-side MOSFET and gate driver circuitry.

Does MPQ2178GQHE-18-AEC1-P require external feedback resistors?

No. As a fixed 1.8V output variant, the FB pin is internally connected to a precision resistor divider and must be left floating per datasheet Section 4 (PIN FUNCTIONS). Adding external resistors will disrupt regulation and may cause overvoltage or instability.

How does the power good (PG) pin behave during startup and fault conditions?

PG asserts high when VFB reaches ≥90% of 0.6V (≥540mV) and deasserts low when VFB drops ≤85% (≤510mV). During short-circuit or overvoltage faults, PG pulls low within 2µs, providing immediate system-level fault indication without software polling.

Can MPQ2178GQHE-18-AEC1-P operate with 100% duty cycle?

Yes. The device supports 100% duty cycle operation in dropout mode when VIN approaches VOUT, maintaining regulation down to VIN = VOUT + 0.5V. This enables stable 1.8V output even during automotive cold-crank events dipping to 2.5V input.

What is the purpose of the wettable flank feature in the QFN-8 package?

The wettable flank design exposes vertical metal sidewalls on all eight leads, enabling automated optical inspection (AOI) of solder fillet quality during reflow. This is mandatory for zero-defect automotive manufacturing and improves field reliability by detecting head-in-pillow or insufficient wetting defects.

Is soft-start time adjustable, and what capacitor value achieves ~1ms ramp?

Yes. With internal 3µA SS charge current, a 330pF capacitor yields ~0.1ms; for ~1ms, use 3.3nF. Minimum recommended value is 1nF. Larger values increase startup time but reduce inrush - critical for avoiding brownout in downstream FPGAs or microcontrollers.

Does MPQ2178GQHE-18-AEC1-P support pre-biased output startup?

Yes. The device incorporates pre-biased start-up functionality: when EN is asserted, it begins switching even if VOUT is already biased to 1.8V, preventing reverse current flow and ensuring safe, controlled ramp-up without damaging downstream loads.